Washboard



C. T. GILBERT Nov. 6, 1934.

WASHBOARD F iled June 18, 1934 gwuento c CHARLES 7? 6115537 PatentedNov. 6, 1934 PATENT OFFICE WASHBOARD Charles '1. Gilbert, Saginaw, Mich,assignor to National Washboard Company, Chicago, 111., a

corporation of West Virginia Application June 18, 1934, Serial No.731,096

3 Claims.

. This invention relates to wash-boards and pertains more particularlyto improvements in a Wash-board rubbing face structure of the kindhaving ribs and grooves or valleys of approxi- 255 mately equal widththat extend in the direction of rubbing, lengthwise of the wash-board.Such arrangement of the corrugations is shown and described in acopending application, Serial No. 724,314, filed May '7, 1934, and inanother copend-s ing application, Serial No. 724,700, filed May 9, 1934I haveshown a double-faced board wherein the corrugations of one of thetwo faces extend up and down, that is, lengthwise of the washboard. Bothof said applications and my present invention are owned by a commonassignee of record. In those applications it is set forth that a rubbingsurface having ribs and valleys extending in the direction of rubbing isadvantageous because the area of working contact between a 2t) handfulof goods and the rubbing surface is much greater than with a surfacehaving horizontally extending ribs, the speed of washing is increased,the amount of pressure required to be exerted against the board isreduced, and stretching and other harmful effects on delicate fabricsare minimized. Also, there is better drainage from the clothes whilethey are being rubbed.

The improved rubbing face structure herein described diifers from thestructures shown in both of the above-mentioned copending applicationsin respect to the crests of the up-and-down ribs and the bottom and sidewalls of the intervening grooves, whereby the objects are attained.

The objects of my present improvement are, to produce as an article ofmanufacture a rubbing surface capable of washing Without straining,tearing or stretching, such delicate fabrics as laces, articles made ofartificial silk, sleazy fabrics, lingerie and the like; to minimize thecost of manufacture of rubbing elements of that character by providing arib-and-valley structure having maximum resistance to springing orbending with minimum weight and thickness of material; and to improvethe appearance of the washboard.

With the foregoing and certain other objects in view, which will appearlater in the specifications, my invention comprises the devicesdescribed and claimed and the equivalents thereof. It is to beunderstood that specific embodiments herein illustrated and describedare chosen as preferred structures typical of others that may beconstructed by those skilled in the art, and that the invention setforth in the appended claims is not i1= intended to be limited furtherthan is required to distinguish from wash-board rubbing elements knownbefore.

Fig. l is a front view of a Wash-board showing a fragmentary rubbingsurface made according to my invention.

Fig. 2 is a horizontal sectional view on line 22 of Fig. 1.

Figs. 3, 4 and 5 are detail views, showing various preferred novel formsof ribs and valleys for the sheet metal rubbing element.

As is clearly shown in the drawing, the rubbing element to which mypresent improvement is applicable comprises a sheet formed with parallelcorrugations that extend up-and-down lengthwise of the board. Thesecorrugations 70 present laterally alternating ribs 1 and grooves 2,their general shape in cross section may be ogee curves that define aseries of crests and valleys extending from the top 3 of the rubbingsurface of the wash-board to its bottom 4. Any other than ogee shapedcorrugations may be employed if desired.

In the form shown in Figs. 3 and 5 the valleys 2 between the ribs 1, andpreferably also the side walls 5 of the ribs, are embossed so as topresent a great number of humps, bulges or raised portions 7 which areseparated from each other by depressions 8.

The bulges '7 may be formed by first embossing a flat sheet of thinmetal according to an appropriate pattern, such as a multitude ofconventional diamond shapes, or any other fine design, and then passingthe embossed sheet through corrugating rollers to form the ribs 1 andvalleys 2, the height of the embossments in the valleys 2 beingpractically the same as in the original em bossed sheet, while theembossments up the sides 5 of the ribs are somewhat flattened, and onthe crest 6 of each rib the surface 6a is nearly smooth, the embossmentsshowing slightly as in Fig. 3, or scarcely at all.

Another satisfactory arrangement of the rubbing surface is obtained byforming in a flat sheet embossments of the pattern desired for thevalleys and side walls, the embossed areas being in the form of parallelbands spaced apart, the intermediate parts of the sheet being leftsmooth, then passing the sheet through corrugating rolls so that thesmooth portions of the sheet will become the crests 6 of the ribs 1, asshown in Fig. 5, and the embossed parts will become the valley bottoms 2and the side walls 5.

The rubbing surface herein described possesses characteristics that makeit greatly superior to surfaces heretofore used. The rubbing is done 1ribs produce a'relatively small amount ofvinterference ,torubbing.smooth, as shown in Fig. 4, or as previously deup and down lengthwise ofthe ribs, and a handful of delicate fabrics being rubbed ridesprincipally on the rib crests but fills the grooves 2 and in them issubjected to the rubbing action of the embossments '7 on the bottom andside walls 2, 5. The goods are not subject to any appreciable rubbingstrains at the smooth, or approximately smooth crests 6 of the ribs 1.Since the face of the mass of wet goods squeezes into and fills thegrooves, it will have a very much larger total area exposed to therubbing action of the embosse ments at 7 and 5 than the same handfulwould have if it were rubber crosswise of the corrugations.

self lengthwise to the contour of the grooves 2 and consequently thetotal width of the area being worked is the developed instead of'theprojected area of the corrugated sheet.

According to this invention, the crests 6 of the They may be perfectlyscribed; they may have only slight bulges and depressions, Fig. 3. Thecrests 6, therefore, form a series of supporting surfaces to take mostof the rubbing pressure load, somewhat like a series of parallel tracks,up and down which the mass This will be apparent whenit is rememberedthat the face of the mass of goods fits it-- of the grooves, or both.Excessive rubbing pressure on the goods is avoided, because the smoothcrests 6 take most of the load and only slight pressure can be exertedon the embossments at the bottoms of valleys 2. The vertical dispositionof the grooves 2 affords perfect drainage.

Having thus described my invention, what I claimand desire to secure byLetters Patent is:

1. A rubbing element for Wash-boards comprising a sheet metal structurepresenting alternating parallel ribs and grooves or valleys disposedlengthwise of the direction of rubbing, the bottoms of said valleysbeing formed with a plurality .of embossments spaced apart, the crestsof the ribs being substantially smooth.

2. A structure as set forth in claim 1 wherein the side walls of theribs below the crests are formed with alternating raised portions anddepressions.

3. A rubbing element for wash-boards comprisinga plate-like memberhaving a surface thereof formed to present alternating parallel ribs andvalleys of substantially equal width disposed of said ribs beingsubstantially smooth, the Workengaging faces. of the valleys beingformed with raised portions alternating with depressions, the raisedportions in the bottoms of the valleys being more pronounced than thoseon the side walls thereof.

CHARLES T. GILBERT.

lengthwise of the direction of rubbing, the crests

